Drilling shafts



1967 D. F. WINBERG 3,301,581

DRILLING SHAFTS Filed Sept. 30, 1965 5 Sheets-Sheet l INVENTOR ATTORNEY5 Dal/Gus A W/Msem;

2W4, 6 4 g fix-My Jan. 31, 1967 Q V wmB G 3,301,581

DRILLING SHAFTS Filed Sept. 30, 1965 '5 Sheets-Sheet z INVENTOR Dal/GusA VIM/852G ATTORNEYs 19.67 v D. F. WINBERG DRILLING SHAFTS Filed Sept.50, 1965 5 Sheets-Sheet :5

' Filed Sept. 30, 1965' I D. F. WINBERG DRILLING SHA'PTS Jan. 31,. 19675 Sheets-Sheet 4 INV DOUGLAS E BY Kl 7 0 K (jug/j A T TOR NE YS Jan. 31,1967.

Filed Sept. 30, 1965 D. F; WINBERG 3,3(31581 DRILLING SHAFTS UnitedStates Patent This application isa continuation-impart of copendingapplication Serial No. 314,142, filed October 7, l963, a nd entitledSectional DrillingShafts, and I now Patent No. 3,258,283. V p

The present invention relates to improvements in drilling shafts orstems, and more particularly'to the provision of a high torque .drillingshaft of sectional constructionand characterized in' part by. a novelnonthreaded tool joint construction. '1 4 In earth boring operationsaccording to therotary drilling method, the work: is. accomplishedthrough the use of an elongated drilling shaft, at. the lowerextremityof which is placed the cutting tool. [Through the inter mediacyof the drilling shaft the cutting tool is rotated and either pushed orpulled (e.g. as in a. raise drilling.

11:; joint components; In'other forms of tool joint accord-. ing to theinvention the pin and box opening are comple--- operation) against theworktace of theinaterial being drilled. Basically, the. drilling shaft,consists of-the cutting tool, drill collars, lengths of drill pipesuccessively interconnected by .tool joints,. 7, and the. kelly 'orgrief stern by which the shaftisattachedtoa drive. mechanism.

Known .vconventionaltool 'joints 'are merely threaded connectionsconsisting of an internally threaded box constituting an end of a firstmember or component of the drillig shaft (e.g. a length of drillpipe)and.. an. externally threaded pin constituting an end ofasecondfrnernher or component of saidshaft. The said first and sec-.

ond members or com-ponents are joined or coupled-to.-

gether by. merely screwing-the said pinfint'o the saidbox, This type ofjoint construction provedto be unsatisfactory for use in high torqueoperations, such as in raise drilling operations, for example,becausethe high torque to which the drilling shaft is subjected in suchoperations tends to. tie the threads .together, making it extremelydifiicult,

and in some cases practically impossible, to unthread the joints forremoval of lengths of drill pipe from the upper end of the drillingshaft. In raise drilling operations, tensile forces also accountforthread distortionor tying. This is because the drilling shaft is intension and the tensile forces .are carried by or. transmitted. throughthe joints solely by the threads.

A further disadvantage of threaded tool joints is that when such areemployed each length of .drill pipe being added to or removed from thedrilling shaft .must be both rotatedand moved endwise an amount equal tothe pitch of the threads per each threehundredand sixty degrees (360) ofrotation. Since in most installations the lengths of drill pipe are'toolarge and too heavy to be handled by hand, the drilling rig must beequipped with a mechanism for causing synchronous rotary and rectilinearmovement of the drill pipe. Known mechanisms of this sort are highlycomplicated, are subject to breakdowns that stop the work, and ingeneral are quite costly,

disadvantages that accompany the use of threaded tool joints. Theunique-tool joint construction provided by- .z; j effecting synchronousrotary and rectilinear movements of the lengths of drill pipe beingadded to or through side wallmeans of said pin and box, and defined:

3,301,581 v Patented Jan. 31, 1967 ice the invention is in the nature ofslip joint, and completely obviates the problem of thread tying ordistorti'on, .and further-obviates the need of a mechanism for removedfrom the drilling shaft. e

Y. -Characteristically, the tool joint of the present inventioncomprises an elongated non-threaded pin interfittingly en.-

gageable within the elongated non-threaded socket opening of a box, anda coupling assembly consisting of a pair of plug elements, at, least aportion of which is frustro-coni cal inv shape,- which elements areinsertable into diametri cally opposed frustro conical-. bores extendinglaterally by two pairs of complementary inwardly tapering openingsformedin said side-wallmeans; and a coupling bolt insertable through anaxial bore in one of the cones andthreadably engageable into an axialbore of the other.

In some forms of tool joint'according to the invention, the pin and boxopening are cylindrical, and compressive stresses are essentially.transferred from one length of.

drill pipe to the next by way of surface-to-surface contactbetweenshoulder and terminal portions of the pinand box mentary tapered,and the compressive stresses are transferred by way ofsurface-to-surfacev contact between the contactingside walls of the pinand the box opening. In

all forms the tensile andtorsional stresses are transmitted through thejoint from one length of drill pipe to the-next length by the couplingassembly.

In the joint form involving a cylindrical pin and a cylindrical boxopening the tolerances at the joint between the several surfaces of saidpin and box opening are relatively close, in the order of a thousandthof an inch, for example. In the joint form involving a tapered pin andmatching tapered box opening the pin is preferably driven into tightcontact with the inside wall of thebox opening. Owing to either theclose tolerance or tight 1 fit, in both forms the joint behaves duringbending in essentially the same Way as an intermediate straight sectionDuring bending the curvaand has an opening in its mid-portion that isgenerallyaligned with the tapered side wall openings. The box portion ofthe joint is essentially the same as before. Also as before, thecoupling assembly comprises a pair of plug elements and aninterconnecting bolt, but such plug elements are somewhat different inform. They are longer and are each characterized by an inwardlytapering, preferably frustro-conical, outboardportion, and a generallystraight, preferably cylindrical, inboard portion. The outboard portionsof such elements fit into the side wall bores as in the previous forms,and the inboard portions thereof snugly fit into the opening in thetransverse support member. Owing to this arrangement, both ends of theplug elements are supported by pin joint component, and the couplingbolt is centrally supported against bendmg.

The novel slip joint constructions of the present invention are notlimited in use to the interconnection of successive lengths of drillpipe, but rather may be used for connecting together any two successiveelement or components of the drilling shaft, such as the drill bit orcutterhead to the drill collar, the drill collar to the drill pipe, andthe drill pipe to the kelly, for example. Also, such slip jointconstructions may have utility in other installations completely foreignto earth boring but requiring the interconnection of tubular and perhapssolid members.

Another principal object of the invention is to provide, as a newarticle of commerce, an improved form or type of drill pipe, such formbeing characterized by an generally straight tubular body orintermediate portion, a right cylindrical or frustro-conical pin at oneend, and a box at the other end having a right cylindrical orfrustroconical box opening, with diametrically opposed, inwardlytapering openings extending laterally through both the pin and the box,and with the openings in the pin corresponding in taper to the openingsin the box. According to the invention, the drill pipe may be eitherinternally or externally upset at the ends and the joint components,i.e., the pin and the box, may be fashioned from the upset end portions.Alternatively, the pin and box may be swaged onto the ends of acylindrical section of drill pipe, or the pin and/or the box may beconstructed as separate fittings to be welded or otherwise suitablyfastened to the ends of a length of drill pipe.

In comparison to conventional threaded tool joints, ad ditionaladvantages gained by using the non-threaded, slip joint of the presentinvention include:

(a) A drilling shaft constructed according to the invention andemploying the slip joint of the invention, is more readily assembled anddisassembled, both in terms of the handling required and speed;

(b) The coupling assembly is wear compensating, i.e., wear on the plugelements and/or the frustro-conical bores is taken up by merelythreading the coupling bolt an additional amount into the interiorlythreaded plug element, so as to locate the plug elements closer togetherin the bores and put them once again in tight engagement with the sidesurfaces of such bores; and

(c) The several elements of the coupling assembly are relativelyinexpensive to manufacture and hence are inexpensive to replace whenthey wear out or are lost.

These and other objects, features, advantages and characteristics of thedrilling shafts, drill pipe and non-threaded tool joints of the presentinvention will be apparent from the following description of typical andtherefore nonlimitive embodiments thereof, taken together with theaccompanying illustrations wherein like letters and numerals refer tolike parts, and wherein:

FIG. 1 is a small scale view of a raise drilling machine in operation assame is forming a pilot hole on a downward pass, the separation betweenthe upper level and the lower level shaft between which the raise is torun being fragmented for simplicity of illustration, with said machinebeing equipped with a drilling shaft embodying features of the presentinvention;

FIG. 2 is an enlarged scale detail view of a tool joint constructiontypifying one form of the invention, with the coupling bolt shown inelevation in such view, and with the remaining elements shown insection;

FIG. 3 is an exploded perspective view of the tool joint of FIG. 2;

FIG. 4 is a view partly in medial longitudinal section, and partly inelevation, of a length of drill pipe, shown in the form of a one-piececasting;

FIG. 5 is a view similar to FIG. 4, showing a modified form ofconstruction of the length of a drill pipe, namely, a composite form;

FIG. 6 is a cross-sectional view of the length of drill pipe shown inFIG. 4, such view being taken substantially along the line 66 of FIG. 4;

FIG. 7 is a cross-sectional view of the length of drill pipe shown inFIG. 5, such view being taken substan tially along line 7-7 of FIG. 5;

FIG. 8 is an exploded elevational view of a fragmented lower portion ofthe drill stem such view illustrating a drill collar especiallyconstructed for coupling a conventional drill bit to the lowermostlength of drill pipe;

FIG. 9 is a view like FIG. 4, but of a modified form of drill pipe;

FIG. 10 is a view like FIG. 2, but of a joint construc tion involvingthe FIG. 9 form of drill pipe;

FIG. 11 also is a view like FIG. 4, but entirely in medial section andof still another modified form of drill FIG. 12 also is a view like FIG.2, but of a joint involving the FIG. 11 form of drill pipe and themodified form of plug elements; and

FIG. 13 is a cross-sectional view taken substantially along line 1313 ofFIG. 12.

Referring to the several figures of the drawing more specifically, theraise drilling mechanism illustrated in FIG. 1 in general comprises acrawler or tractor C, a base member or footing B, and a rotary drillingrig D. The rotary drilling rig D includes a gear reducer 10 mounted onguide sleeves 12 for rectilinear movement along mastlike guide columns14. A kelly or grief stem (not shown) is attached to the output of shaft(not shown) of the gear reducer 10. A sectional drilling shaft S isrotated and carried by the said kelly. Such drilling shaft includes aninternal fluid passageway extending from end to end through which asuitable drilling fluid is delivered to the cutting tool and the workface of the hole being drilled.

The drilling operation involves first boring a small pilot hole from theupper level UL where the drilling mechanism is situated down to a lowerlevel LL. The pilothole drill bit DB is of suitable size to leave thepilot hole PH just slightly larger than the drill stem S. Drilling ofthe pilot hole PH is commenced with the gear reducer 10 in its raisedposition. Then the drilling shaft S is rotated while the gear reducer 10is hydraulically or otherwise suitably urged downwardly. When thedrilling has proceeded to the point where the guide sleeves 12 and thegear reducer 10 have reached about their lowermost extent of travel onguide columns 14, the downward movement thereof is ceased, the portionof the drilling shaft S then in the ground is uncoupled from the kelly,and the gear reducer 10 is returned to its raised position. A length ofdrill pipe L is then coupled between the kelly and the portion of thedrilling shaft S that is in the ground, and then the drilling isresumed. The pilot hole drilling operation thus progresses with'successively introduced lengths L of drill pipe and. downward workstrokes until the pilot hole is formed through the mineral formation Mbetween the upper level UL and the lower level shaft LL. 7

With the pilot hole .pH formed, the pilot hole drill bit DB is removedfrom the drill stern S and a raise cutterhead (not shown) is connectedto the lower end of the drill stern S. The raise hole drilling operationis then commenced. This involves simultaneously rotating andhydraulically lifting of the drilling shaft S and the raise cutterhead.The raise hole boring operation proceeds with cyclic performance of aworking lift of the drilling shaft S and raise cutterhead, anduncoupling and removal of the upper lengths of drill pipe, a lowering ofthe gear reducer 10, a recoupling of the drilling shaft S to the gearreducer 10, and a further raising of the drill stern S and cutterheadand so on until the raise hole is formed between the lower level shaftLL and the upper level UL.

For a more extensive and comprehensive discussion and disclosure of atypical raise drilling technique, and the mechanism employed therein,reference is made to the copending application of Cannon et 211., SerialNo.

224,756, filed September 19, 1962, and entitled Raise- Drilling Methodand Mechanism. To the extent that it may be necessary for a clearerunderstanding of the present invention, the disclosure of suchapplication is expressly incorporated herein by reference.

Turning now to the features of the present invention, FIG. 4 shows alength L of drill pipe typifying one aspect of the invention, and FIG. 2illustrates a tool joint J typifying another aspect of the invention.

FIGS. 2-13 are substantially drawn to scale and de- .pict ratheraccurately the relative proportions of the several parts of the drillpipe lengths L and of the various coupling elements typifying theinvention.

According to the invention, the lower endof a length L of drill pipe isin the form of a right cylindrical pin 16 and the upper end of suchlength L is in the form of a box 18. Unlike known conventional pins andboxes, pin 16 and box 18 are not threaded. Rather, they form male andfemale parts, respectively, of what may be termed a non-threaded, slipjoint J, retained by a cross pin coupling assembly 20, hereinafter to bedescribed.

As illustrated in FIG. 5, for example, the length L of drill pipe isshown to include an internal upset at each of its ends, designated 22,24, respectively. However, it is to be understood that in certaininstallations, e'.g., in installations requiring greater fluid volumesand reduced pump pressures, the upsets may be external so as to makepossible a larger internal diameter. The purpose of the upsets 22, 24are to give additional wall thickness and strength to the ends of thelengths L of drill pipe.

Referring now to FIG. 2 in particular, the pin 16 of an upper length Lof drill pipe is shown fully accommodated within a right cylindricalopening provided in the box 18, of the lower adjacent length L. Aninterior shoulder 26, formed at the bottom of box 18, abuts thegenerally squared off terminal 28 of the pin 16. In similar fashion, thegenerally squared oif terminal 32 of the box 18 abuts against anexternal shoulder 34 formed at the base of pin 16. A relatively closetolerance is required at joint J between the inside wall of box 18 andthe outside wall of pin 16, between internal shoulder 26 and terminal28, and between terminal 32 and external shoulder 34. This tight fit ofthe pin 16 within the box18 makes joint J behave during bending of thedrill stem S, such as during the pilot hole boring operation wherein thedrill stern S is in compression, essentially the same as if the drillstem S were not broken at such joint I. The close tolerance between theouter cylindrical surface of pin 16 and the inner cylindrical surface ofbox 18 prevents the pin 16 from rocking within the box 18. Also, theclose tolerances between the respective pairs of abutting surfaces ofthe terminals 28, 32 and the shoulders 26, 34 enhances the resistance ofthe joint I to rocking since each prevents the displacement of thesurface against which it abuts, and such displacement is necessary inorder for relative angular rnovernent, i.e. rocking between adjacentlengths of drill pipe,

to occur.

As shown. in FIG. 2, for example, inwardly tapered openings 34, 36extend through the cylindrical wall of box 18 at diametrically opposedlocations and are paired with inwardly tapered openings 38, 40 extendingat diametrically opposed locations through the cylindrical wall of pin16 so as to form a .pair of diametrically opposed, frustro-conical boresat thejoint J. The coupling assembly 20'includes a first frusto-concialplug member or cone 42 which is insertable into one pair of inwardlytapering openings, say openings 36, 40, for example, a secondfrustro-conical plug member or cone 44, insertable into the other pairof aligned tapered openings (i.e., openings 34, 38), and a coupling bolt46. As shown, cone 42 includes a bore 48 sized to accommodate the shankof coupling bolt 46, and a countersink 50 sized to receive andaccommodate the head 52 of such bolt 46. Cone 44 is shown to-beinternally threaded at 55 (FIG. 3) and in effect is'a nut into which thethreaded end 54 of bolt 46 is'screwed. Owing to their taperedconstruction, cones 42,44 are easily inserted into the frustroconicalbores formed by paired openings 34, 38 and 36, 40, respectively. Thecoupling bolt 56 is then easily inserted through cone 42 and screwedinto cone 44.- Cone 44 is prevented from turning by the insertion of anappropriate tool (not shown), similar toa screwdriver, into a slot 56,or the like, provided in the outboard end of cone 44, as the couplingbolt 46 is being turned by another appropriate tool, the end of which'isinserted into the socket opening 58 (shownas being of hexagonal shapemerely by way of typical and therefore non-limitive example). Thethreading ofi bolt 46 into cone 44 draws the cones 42, 44 together andwedges them tightly in the openings 34, 38 and 36, 40.

As an added advantage, owing to the taperednature of cones 42, 44 andthe bores composed of openings 34, 38 and 36, 40, the coupling assemblyautomatically compensates for its own wear and the wear of openings 34,

38 and 36, 40. As the cones 42, 44 and/or thepairs of openings 34, 38and 36, 40 Wear, the bolt 46 is merely threaded a little bit furtherinto cone 44 in order to take up'the wear and place the frustro-conicalsurfaces of the cones 42, 44 into tight engagement with thefrustroconical surfaces of the pairs of openings 34, 38 and 36, 40,respectively. Also, owing to the symmetrical construction of thecoupling assembly about the center line axis of the drilling shaft, theforces carried by said coupling assembly are balanced relative to saidcenter line. Each length L of drill pipe is provided with. wrenchreceiving slots, Such as indicated in FIG. 6 at'60, 62. During theraised hole drilling operation a holding wrench (not shown) is used toengage the drilling shaft at such slots 60, 62 and prevent it fromdropping downwardly into the hole when the upper length of drill pipe isbeing removed therefrom. Since there are no threadsat the joints, thereis no rotation of'the uppermost lengthv of drill pipe relative to theremaining portion of the drill stem, and hence the wrench is not neededto hold-the drilling shaft S against rotation while lengths L are beingadded. During pilot drilling the drilling shafts need not be heldagainst endwise movement because it is fully supported at its lower endby the contact of the drill bit DB with the bottom of the pilot hole PH.

The composite form of drill pipe, designated L' in FIG. 5, hassubstantially the same overall configuration as the one-piece offsetform heretofor described. However, according to this form of theinvention the pin 16 and the box 18' are originally formed as separateelements having inboard end portions 64, 66, respectively, of reduceddiameter and adapted to tightly interfit within the cylindrical bodyportion 68. The pin 16' is welded to one end of a generally straightbody portion 68 mm, and the box 18 is welded to the other end of thebody portion 68 at 72. i

As shown in FIG. 8, a double box collar C, one box 74 being internallythreaded at 76 and the other 'box 18 being constructed according to theinvention, may be used for interconnecting the pin16 of the lower-lengthL of drill pipe with a conventional drill bit DB having a threaded pin78. 'No particular harm is done by the threads of this threadedconnection at' 76, 78 becoming tied together, as collar C and drill bitDB are both relatively short in length and light in weight and onceassembled can later be handled as a unit, i.e. once assembled they neednever be taken apart. Of course, the drill bit DB could be constructedto include a non-threaded pin, like pin 16of length L, and the collarconstructed to in- :clude two non-threaded box ends 18".

Further modified forms of collars according to the in vention included acollar having a threaded pin and nonthreaded box for engagement with anon-threaded pin, and a collar having a non-threaded pin and a threadedbox for connection to a threaded pin.

Referring now to FIG. 9, this figure shows another modified form ofdrill pipe involving a modified form of pin and box construction,designated 80 and 82, respectively. Pin 80 is provided with a pair ofdiametrically opposed, inwardly tapering openings 84, 86 that registerwith complementary openings 80, 90 extending through the side wall ofbox 82. Pin 80 and the box opening possess the same degree of taper andpreferably the outside dimension of pin 80 is such that the pin 80 mustbe driven slightly into the box opening in order to align openings 84,86 with openings 80, 90, respectively, in the axial direction. Thisassures an extremely tight fit between the outer surface of pin 80 andthe inner surface of the box opening, and makes possible the eliminationof the shoulders employed with the cylindrical pin and box constructionshown in FIGS. 1-8, for example. The compressive stresses are carried atthe joints by the complementary tapered surfaces.

The coupling assembly 20, comprising cones 42, 44 and pin 46 is employedin a joint involving pin 80 and box 82 in the same manner as describedabove in connection with FIG. 2.

According to the invention, the length of drill pipe 92, shown in FIG.9, is formed by swage forming the pin 80 out of one end portion of aninitially cylindrical piece of drill pipe, and swage forming the box 82out of the other end portion thereof. While possessing the sameadvantages of the drill pipe shown in FIGS. 4 and 5 as to simplicity andease in joint assembly and disassembly, this form of the inventionfurther possesses the advantages of involving no welded parts norshoulders.

FIGS. 11-13 relate to still another form of nonthreaded tool jointaccording to the present invention, and the drill pipe involved therein.

Referring first to FIG. 11, the pipe length L shown thereby is closelysimilar to the form illustrated by FIG. 5. Such length L comprises atubular body portion 68, a box joint component 18" welded to one end ofsuch body portion 68, and a pin joint component 16" welded to theopposite end of such body portion 68.

With respect to its joint forming features, the box 18" is essentiallyidentical to boxes 18, 18 shown by FIGS. 4 and 5, for example. Itincludes a terminal surface 32", annular wall means forming an axiallyextending, generally cylindrical socket or box opening, a pair ofdiametrically opposed, inwardly tapering openings 34", 36" extendinglaterally through said wall means, and wrenchreceiving recesses 60",62".

Pin 16" is quite similar to pins 16, 16 in FIGS. 4 and 5. It includes anexternal shoulder 30" against which the terminal surface 32" of the nextdrilling shaft component abuts, a terminal surface 28 of its own,annular side wall means forming a central passageway in the pin 16",constituting a reduced diameter end portion of the drilling fluidpassageway in the pipe L", and a pair of diametrically opposed, inwardlytapering openings 38", 40" extending laterally through annular wallmeans. However, in this form pin 16" also includes a transverse supportwall or member 94. The support member 94 is shown to be cast integralwith the annular side wall means of pin 16", but it could be separatelyformed and then welded into place. In any event, it is rigidly attachedto the side wall means of pin 16".

Support member 94 extends longitudinally through the pin portion of thedrilling fluid passageway and divides same into two parallel,substantially D-shaped paths (FIG. 13). The medial plane of member 94coincides with the longitudinal center line axis of pipe L", and suchplane is generally perpendicularly related to the center line axes ofthe tapered openings 38", 40". Member 94 is relatively thick and isprovided with an opening 96 (preferably cylindrical in shape), disposedbetween and generally in line with the tapered openings 38", 40".

As clearly shown by FIGS. 12 and 13, the plug elements 98, aresubstantially longer than plug elements 42, 44, and are of a differentform. They each include an inwardly tapering, preferably frusto-conicaloutboard portion (102, 104) and a substantially straight, preferablycylindrical inboard portion (106, 108). As in the earlier joint forms,the outboard portions 102, 104 of the plug elements 98, 100 fit snuglyinto the bores formed by the complementary openings in theconcentrically related side wall means of the pin and box jointcomponents. The inboard portion 108 of plug element 98 extends part wayinto the opening 96, from its side of member 94, and the inboard portion108 of plug element-100 extends part way into opening 96 from its sideof member 94. The inboard portions 106, 108 of plug elements 98, 100 arerather snugly received in the opening 96. Thus, the plug elements 98,100 are in effect supported at both of their ends by the pin 16", theoutboard ends thereof by the side wall means of the plug and the inboardends by the support member 94.

The head portion 58 of the coupling bolt 46 is countersunk into one ofthe plug elements (plug element 100, for example), as in the other formsof the invention, and the threaded portion 54 of such bolt 46 isthreaded into an internally threaded bore formed in the other plugelement (plug element 98 in FIGS. 12 and 13), also as in the otherforms. Thus, through the inboard portions 106, 108 of the plug elements98, 100, the support member also supports the central portion of thecoupling bolt 46, and substantially prevents it from deflecting orbending.

The plug elements 98, 100 are of such a length relative to the pin 16"that their respective inner ends 110, 112 never abut. A gap Z (FIG. 12),the size of which; is dependent on the amount of wear experienced byplug elements 98, 100, and the bores in which they are situated, alwaysexists between the end surfaces 110,, 112 of the plug elements 98, 100.

The advantage of this latter form of tool joint, involving plug elementswhich are supported at both of their ends by the pin component 16" ofthe joint, is that it is capable of withstanding high torque forceswithout distortion or destruction of the coupling assembly. The plugelements 98, 100 are securely held against lateral turning in theirbores, and the coupling bolt 48 is restrained against bending under theinfluence of high torque and/or tension forces to which the joint issubjected.

Although the drill pipe and drill pipe joint construction presented bythe invention has a particular advantageous application in connectionwith raised joint operations, wherein the high torque condition at thejoints of the drill stem practically prohibits the use of threadedjoint, such joint construction constitutes an improvement in drillingshafts in general and the principles herein disclosed have applicationin all types of drilling or boring operations.

From the foregoing, further variations, modifications, adaptations, andusages of drill pipe and drill pipe joints will be apparent within thescope of the following claims.

What is claimed is:

1. A slip joint construction comprising concentrically related,separable, first and second, tubular, joint forming members, said firstjoint forming member including side wall means forming an axiallyextending socket opening sized to snugly accommodate the second jointforming member, with at least one pair of opposed, inwardly taperingopenings extending laterally through said side wall means, and saidsecond joint forming member including side wall means forming an axiallyextending interior passageway, with at least one pair of opposed,inwardly tapering openings extending laterally through said side wallmeans, and being registerable with the inwardly tapering openings in theside wall means of the first joint forming member, when said secondjoint forming member is engaged in the socket opening of said firstjoint forming member, to form a pair of opposed, in-

wardly tapering bore's, and a transversesnpport member spanning theinterior pasa-geway in said second joint forming member, between'thetapered openings in the side wall means thereof, said support memberbeing rigidly attached to the side wall means of said second jointforming member, and having an opening therein that is generally alignedwith the tapered openings; and coupling means comprising a pair of plugelements having tapered outboard portions sized to snugly fit Within thetapered bores, and inboard portions insertable from opposite directionsinto the opening in said support member, to be engaged thereby, withsaid support member serving to substantially prevent sideways movementofthe inboard end portions of said plug elements, and bolt meansdetachably connectable to said plug elements for pulling them together,and the tapered outboard portions thereof into tight engagement with theside surfaces of the tapered bores.

2. A slip joint construction comprising concentrically related,separable, first and second, tubular, joint forrning members, said firstjoint forming member including side wall means forming an axiallyextending socket opening sized to snugly accommodate the second jointforming member, with at least one pair of opposed, inwardly tapering,frustro-conical openings extending laterally through said side wallmeans, and said second joint forming member including side wall meansforming an axially extending interior passageway, with at least one pairof opposed, inwardly tapering, frustro-conical openings extendinglaterally through said side wall means, and being registerable with thefrustro-conical openings in the side wall means of the first jointforming member, when said second joint forming member is engaged in thesocket opening of said first joint forming member, to form a pair ofopposed, inwardly tapering, frustro-conical bores, and a transversesupport member extending across the open interior of said second jointforming member at a location therein between the frustro-conicalopenings in the side wall means of said second joint forming member,said support member being rigidly attached to the side wall means ofsaid second joint forming member, and having a generally cylindricalopening therein that is general-1y aligned with the frustro-conicalopenings; and coupling means comprising a pair of plug elements havinginwardly tapering, frustro-conical outboard portions sized to snugly fitwithin the frustro-conical bores, and generally cylindrical inboardportions insertable from opposite directions into, and sized to snuglyfit into, the generally cylindrical opening in' said support member,said support member serving to substantially prevent sideways movementof the inboard end portions of said plug elements, and a bolt having anenlarged head at one end and a threaded portion at the other end, withone of said plug elements having'an elongated opening extending axiallytherethrough to accommodate the shank of said bolt, and the other havingan internally threaded, elongated opening therein for receiving thethreaded portion of said bolt, said bolt serving when tightened to drawthe plug elements together, and the outboard portions thereof into tightengagement with the side surfaces of such bores. 3. In a sectional, hightorque drilling shaft, separable, first and second tubular driling shaftelements, each formed to include a central drilling fluid passageway,and a slip-joint connection between said elements, said jointcomprising:

-(a) a tubular box at an end of the first drilling shaft element, saidbox including annular side wall means forming an axial-1y extending bo-xopening, constituting an end portion of the drilling fluid passageway insaid first drilling shaft element, with at least one pair of opposed,inwardly tapering openings extending laterally through said side wallmeans;

-(b) a tubular pin at an end of the second drilling shaft element,insertable into said box opening, said pin. including annular 'side'wall'means forming a interior passageway in the .pin that constitutes areduced diameter end portion of the drilling fluid passageway in saidsecond drilling shaft element, with at least one pair of opposed,inwardly tapering openings extending laterally through said side wallmeans and being registerable with the said inwardly taperingopenings ofsaid box, when the pin is in the box opening, to form a pair of opposed,-inwardly tapering bores, and a transverse support member extendingacross the open interior of said pin, inbetween the inwardly taperingopenings, said support member being rigidly attached to the side wallmeans of said pin, and'having an opening therein that is generallyaligned with the inwardly tapering openings; and

(c) a coupling assembly comprising a pair of elongated plug elementsinsertable into said inwardly tapering bores, and each being ofone-piece form, and each having an inwardly tapering outboard portion oflike taper as its bore, and an inboard portion shaped to snugly fit partway into the opening in said transverse support member, and bolt meansdetachably connectable to said plug elements for pulling them togetherand the outboard portions into tight engagement with the side surfacesof the bores.

4. A slip-joint according to claim 3, wherein the pin inludes anexternal shoulder in abutting engagement with the terminal of said box.

5. A slip-joint between first and second tubular, drilling shaftcomponents, each formed to include a central drilling fluid passageway,said joint comprising:

(a) a tubular box at an end of the first tubular drilling shaftcomponent, said box including annular side wall means forming an axiallyelongated box opening constituting an end portion of the drilling fluidpassageway in said first drilling shaft component, with at least onepair of diametrically opposed, inwardly tapering openings extendinglaterally through said side wall means;

(b) a tubular pin at an end of a second tubular drilling shaftcomponent, insertable into and snugly engageably by said box opening,said pin including annular side wall means forming a central passagewayin the pin constituting the end portion of the drilling fluid pasagewayin said second drilling shaft component, with at least one pair ofdiametrically opposed, inwardly tapering openings extending laterallythrough said side wall means, and being registerable with the saidinwardly tapering openings of the box when the pin is in the box, so asto form a pair of diametrically opposed, inwardly tapering bores, and atransverse support member extending transversely across the openinterior of the pin, inbetween the inwardly tapering openings, saidsupport member being rigidly attached to the side wall means of saidpin, and having an opening therein that is generally aligned with saidinwardly tapering openings; and

(c) a coupling assembly comprising a pair of elongated plug elementshaving tapered out-board portions of like taper as said bores, and sizedto snugly fit within said bores, and an inboard portion shaped and sizedto snugly fit within about a half or less of the opening in saidtransverse support member, and a bolt having an enlarged head at one endand a threaded portion at the other end, with one of said plug elementshaving an elongated opening extending axially therethrough toaccommodate the shank of said bolt, and the other having an internallythreaded, elongated opening therein for receiving the threaded portionof said bolt, said bolt serving when tightened to draw the plug elementstogether, and the outboard portion thereof into tight engagement withthe side surfaces of such bores.

6. A slip-joint according to claim 5, wherein the pin includes anexternal shoulder in abutting engagement with the terminal of said box.

References Cited by the Examiner 5 1 994 791 UNITED STATES PATENTS2,092,372

1/1897 Doyle 285191 2,872,227 8/1902 Merrie et al. 2'85191 6/ 1966Winberg et al. 287-119 FOREIGN PATENTS References Cited by the ApplicantUNITED STATES PATENTS Wachs.

FOREIGN PATENTS Canada.

CARL W. TOMLIN, Primary Examiner.

3/1913 Great Britain.

THOMAS P. CALLAGHAN, Examiner.

1. A SLIP JOINT CONSTRUCTION COMPRISING CONCENTRICALLY RELATED,SEPARABLE, FIRST AND SECOND, TUBULAR, JOINT FORMING MEMBERS, SAID FIRSTJOINT FORMING MEMBER INCLUDING SIDE WALL MEANS FORMING AN AXIALLYEXTENDING SOCKET OPENING SIZED TO SNUGLY ACCOMMODATE THE SECOND JOINTFORMING MEMBER, WITH AT LEAST ONE PAIR OF OPPOSED, INWARDLY TAPERINGOPENINGS EXTENDING LATERALLY THROUGH SAID SIDE WALL MEANS, AND SAIDSECOND JOINT FORMING MEMBER INCLUDING SIDE WALL MEANS FORMING AN AXIALLYEXTENDING INTERIOR PASSAGEWAY, WITH AT LEAST ONE PAIR OF OPPOSED,INWARDLY TAPERING OPENINGS EXTENDING LATERALLY THROUGH SAID SIDE WALLMEANS, AND BEING REGISTERABLE WITH THE INWARDLY TAPERING OPENINGS IN THESIDE WALL MEANS OF THE FIRST JOINT FORMING MEMBER, WHEN SAID SECONDJOINT FORMING MEMBER IS ENGAGED IN THE SOCKET OPENING OF SAID FIRSTJOINT FORMING MEMBER, TO FORM A PAIR OF OPPOSED, INWARDLY TAPERINGBORES, AND A TRANSVERSE SUPPORT MEMBER SPANNING THE INTERIOR PASSAGEWAYIN SAID SECOND JOINT FORMING MEMBER, BETWEEN THE TAPERED OPENINGS IN THESIDE WALL MEANS THEREOF, SAID SUPPORT MEMBER BEING RIGIDLY ATTACHED TOTHE SIDE WALL MEANS OF SAID SECOND JOINT FORMING MEMBER, AND HAVING ANOPENING THEREIN THAT IS GENERALLY ALIGNED WITH THE TAPERED OPENINGS; ANDCOUPLING MEANS COMPRISING A PAIR OF PLUG ELEMENTS HAVING TAPEREDOUTBOARD PORTIONS SIZED TO SNUGLY FIT WITHIN THE TAPERED BORES, ANDINBOARD PORTION INSERTABLE FROM OPPOSITE DIRECTIONS INTO THE OPENING INSAID SUPPORT MEMBER, TO BE ENGAGED THEREBY, WITH SAID SUPPORT MEMBERSERVING TO SUBSTANTIALLY PREVENT SIDEWAYS MOVEMENT OF THE INBOARD ENDPORTIONS OF SAID PLUG ELEMENTS, AND BOLT MEANS DETACHABLY CONNECTABLE TOSAID PLUG ELEMENT FOR PULLING THEM TOGETHER, AND THE TAPERED OUTBOARDPORTIONS THEREOF INTO TIGHT ENGAGEMENT WITH THE SIDE SURFACES OF THETAPERED BORES.